root/drivers/hwmon/da9055-hwmon.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * HWMON Driver for Dialog DA9055
 *
 * Copyright(c) 2012 Dialog Semiconductor Ltd.
 *
 * Author: David Dajun Chen <dchen@diasemi.com>
 */

#include <linux/delay.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/completion.h>

#include <linux/mfd/da9055/core.h>
#include <linux/mfd/da9055/reg.h>

#define DA9055_ADCIN_DIV        102
#define DA9055_VSYS_DIV 85

#define DA9055_ADC_VSYS 0
#define DA9055_ADC_ADCIN1       1
#define DA9055_ADC_ADCIN2       2
#define DA9055_ADC_ADCIN3       3
#define DA9055_ADC_TJUNC        4

struct da9055_hwmon {
        struct da9055   *da9055;
        struct mutex    hwmon_lock;
        struct mutex    irq_lock;
        struct completion done;
};

static const char * const input_names[] = {
        [DA9055_ADC_VSYS]       = "VSYS",
        [DA9055_ADC_ADCIN1]     = "ADC IN1",
        [DA9055_ADC_ADCIN2]     = "ADC IN2",
        [DA9055_ADC_ADCIN3]     = "ADC IN3",
        [DA9055_ADC_TJUNC]      = "CHIP TEMP",
};

static const u8 chan_mux[DA9055_ADC_TJUNC + 1] = {
        [DA9055_ADC_VSYS]       = DA9055_ADC_MUX_VSYS,
        [DA9055_ADC_ADCIN1]     = DA9055_ADC_MUX_ADCIN1,
        [DA9055_ADC_ADCIN2]     = DA9055_ADC_MUX_ADCIN2,
        [DA9055_ADC_ADCIN3]     = DA9055_ADC_MUX_ADCIN3,
        [DA9055_ADC_TJUNC]      = DA9055_ADC_MUX_T_SENSE,
};

static int da9055_adc_manual_read(struct da9055_hwmon *hwmon,
                                        unsigned char channel)
{
        int ret;
        unsigned short calc_data;
        unsigned short data;
        unsigned char mux_sel;
        struct da9055 *da9055 = hwmon->da9055;

        if (channel > DA9055_ADC_TJUNC)
                return -EINVAL;

        mutex_lock(&hwmon->irq_lock);

        /* Selects desired MUX for manual conversion */
        mux_sel = chan_mux[channel] | DA9055_ADC_MAN_CONV;

        ret = da9055_reg_write(da9055, DA9055_REG_ADC_MAN, mux_sel);
        if (ret < 0)
                goto err;

        /* Wait for an interrupt */
        if (!wait_for_completion_timeout(&hwmon->done,
                                        msecs_to_jiffies(500))) {
                dev_err(da9055->dev,
                        "timeout waiting for ADC conversion interrupt\n");
                ret = -ETIMEDOUT;
                goto err;
        }

        ret = da9055_reg_read(da9055, DA9055_REG_ADC_RES_H);
        if (ret < 0)
                goto err;

        calc_data = (unsigned short)ret;
        data = calc_data << 2;

        ret = da9055_reg_read(da9055, DA9055_REG_ADC_RES_L);
        if (ret < 0)
                goto err;

        calc_data = (unsigned short)(ret & DA9055_ADC_LSB_MASK);
        data |= calc_data;

        ret = data;

err:
        mutex_unlock(&hwmon->irq_lock);
        return ret;
}

static irqreturn_t da9055_auxadc_irq(int irq, void *irq_data)
{
        struct da9055_hwmon *hwmon = irq_data;

        complete(&hwmon->done);

        return IRQ_HANDLED;
}

/* Conversion function for VSYS and ADCINx */
static inline int volt_reg_to_mv(int value, int channel)
{
        if (channel == DA9055_ADC_VSYS)
                return DIV_ROUND_CLOSEST(value * 1000, DA9055_VSYS_DIV) + 2500;
        else
                return DIV_ROUND_CLOSEST(value * 1000, DA9055_ADCIN_DIV);
}

static int da9055_enable_auto_mode(struct da9055 *da9055, int channel)
{

        return da9055_reg_update(da9055, DA9055_REG_ADC_CONT, 1 << channel,
                                1 << channel);

}

static int da9055_disable_auto_mode(struct da9055 *da9055, int channel)
{

        return da9055_reg_update(da9055, DA9055_REG_ADC_CONT, 1 << channel, 0);
}

static ssize_t da9055_auto_ch_show(struct device *dev,
                                   struct device_attribute *devattr,
                                   char *buf)
{
        struct da9055_hwmon *hwmon = dev_get_drvdata(dev);
        int ret, adc;
        int channel = to_sensor_dev_attr(devattr)->index;

        mutex_lock(&hwmon->hwmon_lock);

        ret = da9055_enable_auto_mode(hwmon->da9055, channel);
        if (ret < 0)
                goto hwmon_err;

        usleep_range(10000, 10500);

        adc = da9055_reg_read(hwmon->da9055, DA9055_REG_VSYS_RES + channel);
        if (adc < 0) {
                ret = adc;
                goto hwmon_err_release;
        }

        ret = da9055_disable_auto_mode(hwmon->da9055, channel);
        if (ret < 0)
                goto hwmon_err;

        mutex_unlock(&hwmon->hwmon_lock);

        return sprintf(buf, "%d\n", volt_reg_to_mv(adc, channel));

hwmon_err_release:
        da9055_disable_auto_mode(hwmon->da9055, channel);
hwmon_err:
        mutex_unlock(&hwmon->hwmon_lock);
        return ret;
}

static ssize_t da9055_tjunc_show(struct device *dev,
                                 struct device_attribute *devattr, char *buf)
{
        struct da9055_hwmon *hwmon = dev_get_drvdata(dev);
        int tjunc;
        int toffset;

        tjunc = da9055_adc_manual_read(hwmon, DA9055_ADC_TJUNC);
        if (tjunc < 0)
                return tjunc;

        toffset = da9055_reg_read(hwmon->da9055, DA9055_REG_T_OFFSET);
        if (toffset < 0)
                return toffset;

        /*
         * Degrees celsius = -0.4084 * (ADC_RES - T_OFFSET) + 307.6332
         * T_OFFSET is a trim value used to improve accuracy of the result
         */
        return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(-4084 * (tjunc - toffset)
                                                        + 3076332, 10000));
}

static ssize_t label_show(struct device *dev,
                          struct device_attribute *devattr, char *buf)
{
        return sprintf(buf, "%s\n",
                       input_names[to_sensor_dev_attr(devattr)->index]);
}

static SENSOR_DEVICE_ATTR_RO(in0_input, da9055_auto_ch, DA9055_ADC_VSYS);
static SENSOR_DEVICE_ATTR_RO(in0_label, label, DA9055_ADC_VSYS);
static SENSOR_DEVICE_ATTR_RO(in1_input, da9055_auto_ch, DA9055_ADC_ADCIN1);
static SENSOR_DEVICE_ATTR_RO(in1_label, label, DA9055_ADC_ADCIN1);
static SENSOR_DEVICE_ATTR_RO(in2_input, da9055_auto_ch, DA9055_ADC_ADCIN2);
static SENSOR_DEVICE_ATTR_RO(in2_label, label, DA9055_ADC_ADCIN2);
static SENSOR_DEVICE_ATTR_RO(in3_input, da9055_auto_ch, DA9055_ADC_ADCIN3);
static SENSOR_DEVICE_ATTR_RO(in3_label, label, DA9055_ADC_ADCIN3);

static SENSOR_DEVICE_ATTR_RO(temp1_input, da9055_tjunc, DA9055_ADC_TJUNC);
static SENSOR_DEVICE_ATTR_RO(temp1_label, label, DA9055_ADC_TJUNC);

static struct attribute *da9055_attrs[] = {
        &sensor_dev_attr_in0_input.dev_attr.attr,
        &sensor_dev_attr_in0_label.dev_attr.attr,
        &sensor_dev_attr_in1_input.dev_attr.attr,
        &sensor_dev_attr_in1_label.dev_attr.attr,
        &sensor_dev_attr_in2_input.dev_attr.attr,
        &sensor_dev_attr_in2_label.dev_attr.attr,
        &sensor_dev_attr_in3_input.dev_attr.attr,
        &sensor_dev_attr_in3_label.dev_attr.attr,

        &sensor_dev_attr_temp1_input.dev_attr.attr,
        &sensor_dev_attr_temp1_label.dev_attr.attr,
        NULL
};

ATTRIBUTE_GROUPS(da9055);

static int da9055_hwmon_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct da9055_hwmon *hwmon;
        struct device *hwmon_dev;
        int hwmon_irq, ret;

        hwmon = devm_kzalloc(dev, sizeof(struct da9055_hwmon), GFP_KERNEL);
        if (!hwmon)
                return -ENOMEM;

        mutex_init(&hwmon->hwmon_lock);
        mutex_init(&hwmon->irq_lock);

        init_completion(&hwmon->done);
        hwmon->da9055 = dev_get_drvdata(pdev->dev.parent);

        hwmon_irq = platform_get_irq_byname(pdev, "HWMON");
        if (hwmon_irq < 0)
                return hwmon_irq;

        ret = devm_request_threaded_irq(&pdev->dev, hwmon_irq,
                                        NULL, da9055_auxadc_irq,
                                        IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
                                        "adc-irq", hwmon);
        if (ret != 0) {
                dev_err(hwmon->da9055->dev, "DA9055 ADC IRQ failed ret=%d\n",
                        ret);
                return ret;
        }

        hwmon_dev = devm_hwmon_device_register_with_groups(dev, "da9055",
                                                           hwmon,
                                                           da9055_groups);
        return PTR_ERR_OR_ZERO(hwmon_dev);
}

static struct platform_driver da9055_hwmon_driver = {
        .probe = da9055_hwmon_probe,
        .driver = {
                .name = "da9055-hwmon",
        },
};

module_platform_driver(da9055_hwmon_driver);

MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
MODULE_DESCRIPTION("DA9055 HWMON driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9055-hwmon");